TWO-WAVELENGTH TUBE, LIGHTING APPARATUS FOR INSPECTION, INSPECTION APPARATUS AND INSPECTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a lighting apparatus for inspection capable of visually and clearly detecting whether or not a defect such as defocussing inferiority or the like is present on a fine surface to be processed of the resist pattern or the like formed on a semiconductor substrate such as a wafer or the like and especially enhanced in visibility by widening the angle of visibility. SOLUTION: The two-wavelength tube having peak wavelengths of respective colors in a complementary color relation and capable of emitting two kinds of coherent lights narrow in wavelength region is provided. The two-wavelength tube is especially constituted of a fluorescent tube coated with a plurality of phosphors capable of emitting two kinds of coherent lights or a discharge tube filled with gas capable of emitting two kinds of coherent lights. A surface 16 to be processed of a predetermined pattern formed on a substrate 18 is irradiated with the coherent lights 14 from the light source of the lighting apparatus 12 for inspection and, on the basis of the diffracted light 22 from the fine surface 16 to be processed, it is judged whether or not the fine surface 16 to be processed is deformed from the predetermined pattern. The lighting apparatus 12 is constituted so that the irradiating coherent lights 14 have peak wavelengths of respective colors in complementary color relation and have a narrow wavelength region.